How To Fix CNV455 - Generation cannot run in more than one client at a time

SAP Error Message - Details

• Message type: E = Error

• Message class: CNV - Conversion: Messages for Conversion Services (CNCC)

• Message number: 455

• Message text: Generation cannot run in more than one client at a time

What causes this issue?

The generation process is active in other clients.

System Response

Program is canceled.

How to fix this error?

Wait until the generation in the other clients is completed, then
restart this program.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message CNV455 - Generation cannot run in more than one client at a time ?

  The SAP error message CNV455 indicates that a specific process or job cannot be executed in more than one client at the same time. This is often encountered during data migration or conversion processes, particularly when using SAP's tools for data migration, such as the SAP S/4HANA Migration Cockpit or other conversion tools.
  Cause:
  
  Concurrent Execution: The error typically arises when there are multiple sessions or jobs trying to execute the same migration or conversion process across different clients simultaneously.
  Locking Mechanism: SAP has a locking mechanism to prevent data inconsistencies and ensure that the migration process is not disrupted by concurrent operations.
  Client-Specific Data: The migration process may involve client-specific data, and running it in multiple clients at the same time could lead to conflicts or data integrity issues.
  
  Solution:
  
  Single Client Execution: Ensure that the migration or conversion job is only running in one client at a time. You may need to check other sessions or jobs that might be executing the same process.
  Job Monitoring: Use transaction codes like SM37 to monitor background jobs and ensure that no other jobs are running that could conflict with the migration process.
  Client Locking: If you are using a multi-client environment, make sure to lock the client for the duration of the migration process. This can be done by coordinating with your team to schedule the migration during a maintenance window.
  Error Handling: If the error persists, check the logs for more detailed information about what might be causing the issue. You can use transaction SLG1 to view application logs related to the migration process.
  
  Related Information:
  
  Documentation: Refer to the official SAP documentation for the specific migration tool you are using, as it may provide additional insights or troubleshooting steps.
  SAP Notes: Check for any relevant SAP Notes that might address this specific error or provide updates and patches that could resolve the issue.
  Community Forums: Engage with the SAP Community or forums where other users may have encountered similar issues and can share their solutions.
  
  By following these steps, you should be able to resolve the CNV455 error and successfully run your migration or conversion process in SAP.